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Lively Duke’s Daughter in the Demon Castle

Chapter Text

Katarina Claes, under the impression that she had successfully avoided all doom flags and cleared the timeline of the Fortune Lover otome game with Maria achieving the Friendship ending, was now in the beginning of her second year at the Magic Academy in the Kingdom of Sorcier. The schoolwork was continuously hard for her, but she was enjoying spending time with her friends. 

Sometimes at the Magic Academy, guest lecturers or similar people would visit. Sometime during the first weeks of their second school year, the Academy received a visit from an Earl Elliott. 

From what her friends explained to Katarina, he was apparently known for collecting magic artifacts of uncertain origins, and now he wanted to showcase one of his latest acquisitions by visiting places of social importance and let people come to view it. Right now, he was at the Academy, borrowing one of the lecture halls as an exhibit room. 

As the most accomplished students at the academy, the student council had been specially invited. And Katarina was sort of an honorary member of the council, so she accompanied them. 

The artifact had been placed on the teacher’s lectern to be viewed, while the Earl stood nearby, telling the story of his find to every new collection of guests. 

The artifact in question had a rectangular shape, an arm in width, less than half of that in depth, more than a hand in height. Katarina would have called it box-shaped, but its surfaces were not flat and its corners were not pointed like one. The corners were rounded, and the surfaces vaguely curved. It had an odd grey color with a very weak sheen. In the middle were a circular protrusion with some simple carvings. Surrounding it was a ring of interlinked almost-squares, and that was surrounded by another ring of such squares, only smaller and greater in number, followed by one more such ring. Each of the squares had their own carvings, hard to see. Several colored stones were symmetrically placed across the surface of the artifact. 

“What can you tell us about this artifact, Earl Elliott?” Geord politely asked. 

“It was excavated from an old ruin in part the borderlands, your highness”, Earl Elliott said. “A structure abandoned when that territory was absorbed into the kingdom. It was estimated that this find had been buried in the cellar for several hundreds of years. Aesthetically, it does not conform to any culture we are familiar with, either nearby or remote. The magic wielders who I had investigate it could all sense something beyond the natural from it, but could not identify its exact magic, and all attempts to activate it have been unsuccessful.” 

While her fiancé talked with the Earl, Katarina and her girl friends walked in a bit closer to the artifact to inspect it. 

“It doesn’t feel like metal, stone or wood”, Maria commented in wonder as she carefully felt the surface of the artifact. 

Katarina took her glove off and felt for herself. Maria was right. It didn’t feel like any of those things. If anything... if she didn’t know better, she would have thought it felt like some kind of hard plastic. 

“I don’t recognize any of these symbols”, Sophia said contemplatively. 

Katarina tried to look at the carvings in the squares, but they were hard to see in the material. She tried to find anything she could easily see, and ended up at the larger circular protrusion in the middle. 

It had a very simple symbol, a circle with a horizontal line inside of it. Something about it stirred something in the back of Katarina’s mind, but she couldn’t quite make out what. She looked it over, then started circling the artifact. Her friends found it odd behavior, but less odd than usual for the girl, so they let her be while they engaged the Earl in conversation. 

On one of her turns, looking at the artifact side-ways, it clicked. The symbol was very similar to a symbol she had been familiar with in her previous life. Except this was the world of Fortune Lover, and it couldn’t be the same type of symbol. Besides, it wasn’t made out in the right direction. 

She walked to the front of the artifact and eyed the symbol. For it to be properly similar to the symbol she was thinking about, the line should be vertical, not horizontal. She looked at the outline of the circular disk and saw that on the underside, there was a thin line across, slightly above the surface of the artifact. It was if the disk was placed atop some other middle disk, and not fully attached to the artifact. 

Not fully attached... 

Some other memories from her last life passed through her head, and she had an idea. 

She placed her hands on both sides of the disk, and lightly pushed in opposite directions. 

“Big Sister, what are you doing?” Keith asked in concern. 

She would have answered, but in the same moment, she felt the disk move under her fingers, and thinking that she had been right, she put more force into her pushing and pulling. 

“Lady Claes, what...” the Earl began in an indignant tone. 

The disk fully moved under her fingers, and spun counter-clockwise until it came to a full stop, the symbol now having its line pointing upwards instead of sideways. The next moment, there was a whooshing sound, and the symbol, all the symbols on the artifact, began to shine with a soft light inside their squares, and the colored stones across the artifact too. 

Everybody yelped, Katarina included as the once seemingly inanimate artifact sprung to life. The kept still for a few moments, then relaxed when the artifact didn’t take any further action. 

“Katarina, what made you think of doing that?” Geord asked, under the surface a little bewildered. 

“Erm, it was my intuition!” Katarina answered. 

She was more surprised than anyone. Why would a magic artifact in this world make use of a power symbol for electronics? Had it been put there by a lazy game designer? But nothing like this had shown up either in the game or any of its promotional art. 

They all moved closer to artifact to inspect it. 

“This is extraordinary”, Earl Elliott said. “I must call in people to re-examine it.” 

Maria moved closer, holding out her hands above the artifact while mildly glowing. 

“I can sense... something”, Maria said uncertainly. “It is not mundane, but it doesn’t feel like magic usually does.” 

Katarina looked over the now easy to see symbols in the smaller squares surrounding the middle disk. They didn’t look like the letters of the common script of Sorcier. 

It didn’t remind her of symbols from Ancient Script either. But she was so bad at Ancient Script, it wouldn’t surprise her if she forgot it the moment they graduated the Academy. 

The only other letters she knew was from Japanese and the western alphabet, and none of the symbols on the artifact really looked like those either. 

Seeing the consistently glowing symbols on the artifact, it was easy for her to spot the single square that was blinking. It was one of the larger squares belonging to the innermost ring of squares surrounding the middle disk. It had a symbol that reminded her of two interlocking chain links, surrounded by outwards radiating semicircles above and below. 

The way it blinked... it reminded her of... 

She put her finger on the square and put force into it. It gave way, slightly sinking down into the artifact accompanied with a swishing sound. 

She flinched away as the stones began to shine brighter and a sound, a dark tone, appeared, growing in strength for every moment. 

“Everybody, back away!” Prince Geord exclaimed. 

“Wait, I’ll turn it off!” Katarina said in a panic and moved forward. 

“No, Katarina!” Geord shouted. 

Katarina placed her hand on the center disk and turned it sideways to the state it had been before. Contrary to what she had thought, though, the light did not turn off, but continued to grow in strength. She began to move to separate from the artifact... 

The light from the device exploded in intensity, blinding everyone in the room. 

There was a truly unfamiliar sound. 

And then the light receded. 

As their eyes readjusted, they could see again. And then promptly froze. 

Katarina was gone. In her place was a stranger, a small girl. 

She looked somewhat smaller than even Sophia. Her long hair, which went as far as her knees, was silver with a lavender tint and bond up with. She was dressed in a colorful pink, lavender and white dress, and wore a yellow headband shaped like a crown. She turned her gaze towards the student council, revealing large, purple eyes with a shine in them that made one think of stars, and a lack of facial expression. 

“Who are you?” the girl asked in a deadpan voice, slightly tilting her head to the side. 


There was a few moments of silence and stillness. Then it broke. 

“Lady Katarina!” Mary shouted in horror. When there was no answer that would reveal that Katarina was still in the room rather than disappeared, Mary swiftly closed in on the stranger girl. “You! What did you do to Lady Katarina?!” 

“Who?” the girl asked, tilting her head even further. 

“She was here, and now she isn’t!” Mary said, beginning to work herself into a state of hysteria. She grabbed the girl by the shoulders and started shaking her. “Where?! Is?! She?!” 

“Mary, take it easy!” Alan intervened, pulling his fiancée away from the girl. 

The girl stared with a hard-to-read expression at Mary for a few moments, and then looked around the lecture hall. 

“This isn’t the treasury”, the girl stated. 

They all stared at her, nonplussed.  

“Pardon, what do you mean, treasury?” Geord stepped forward. 

The girl looked at him. 

“I was visiting the treasury, looking for materials.” 

“What treasury?” Alan asked exasperated while still holding back Mary. 

“The castle treasury”, the girl said, as if obvious. She looked around again. “This doesn’t look like a part of the castle I have been in.” 

“This isn’t a castle, it is the Magic Academy!” Keith said. 

“Magic Academy?” the girl asked, tilting her head. 

Geord studied the girl. Usually, he could read people like a book, given he had at least some minutes. This girl had weird facial expressions, making her unusually hard to read. As best he could tell, she seemed confused, or at least, made the effort to look confused. 

Katarina had disappeared. This girl had turned up, apparently confused, and talked about being in a castle. The apparent conclusion came easy to the prince, but that spawned all manner of other questions. He had to affirm it. 

“Pardon my question, but what happened in the minutes before you found yourself here?” he asked. 

“I was looking for materials in the treasury. I couldn’t find what I needed, so I looked deeper. Then I found this thing.” 

She pointed to the artifact. 

“What do you mean you found it?” Earl Elliott asked dismissively. “This find has been with me since it was excavated.” 

“It looked weird, so I tried to make it work to see if it was useful”, the girl continued as if she hadn’t heard the Earl. “But all I could make it do was make lights blink. Weird.” 

The color of Earl Elliott’s face rose, but when he made a move to talk, Geord stopped him with a gesture. 

“Then there was a weird sound and flash of light... and now I am here. Where is here?” The girl looked around. 

Geord had studied the girl’s facial expressions for all of her explanation. Now he turned his thoughts inwards. 

If you took it at face value, the girl had been magically transported here from somewhere else. Meaning Katarina had likely done the same, only the other way around. Since it had happened simultaneously, it followed that they had swapped positions with each other. And by that logic, there must be two artifacts: one here, and one wherever the girl had come from. If that was true, hopefully Katarina had not faced any harm from whatever the artifact had done. 

Geord turned his attention to the girl again. He needed more facts, and she was his only venue right now. It was a little belated, but it was time to put it all into his social mask. He formally placed his hand to his chest. 

“My apologies for my lack of manners. I offer you greetings. I am Prince Geord Stuart, of the Kingdom of Sorcier.” 

“Oh”, the girl said matter-of-factly. She made a small curtsy. “I am Princess Aurora Syalis Goodereste, of the kingdom of Goodereste.” 

Geord looked at her, keeping a solid lid on his usual poker face. Did this girl seriously just proclaim herself a princess? And of the kingdom of Goodereste? He had never heard of it, and he had studied many countries growing up as a royal. He could see the others’ plainer disbelief at the proclamation. 

Thing was, if the girl was making things up, there were more believable stories she could tell. It was possible that she wasn’t even clever enough to realize the absurdity of such a claim – something about her facial expressions seemed off from the beginning – but if that was so, she was most likely nothing at all for him to handle, and thus not a problem or a threat. 

It was also possible that she might be putting on an act in order to seem dimwitted and harmless in order to gain something. Magical transportation seemed to fit the line of events, but didn’t exclude there was some plot involved rather than the accident the girl acted as if it was. If so, he needed more time with her in order to ascertain it and dismantle it. Calling her out on it before he had any proof or knowledge to justify it wouldn’t be wise. 

Since his thinking always considered every angle, he also thought about the possibility that it was the simple truth the girl was stating, no matter how improbable it sounded. If she was actual royalty, it wouldn’t do to not give her the respect and etiquette beholden her station. It could cause a diplomatic incident, it may so be with a country that if it existed, it didn’t exist near Sorcier. 

All matters considered, it was better to indulge her claim and act as if it were true, until the situation changed. Hopefully the others would realize the same enough that he didn’t have to state it out loud before the stranger. 

“Well met, Princess Aurora”, he concluded his greetings. 

“Oh, I go by Sya”, the girl said. “Even though most just call me Princess.” 

“Very well, Princess Sya”, Geord admonished. “If I may ask, is there anything else you know about this artifact?” 

“Not a thing. I just found it at the back of the treasury with all manners of oddities. I just pressed and turned at random, I never understood what it did.” 

That didn’t sound like the best way to handle an unfamiliar magic artifact. If the girl was genuine rather than putting on an act, she didn’t give the impression of possessing good common sense. 

Geord turned to his fellow student council members. 

“Could you all arrange for a private room and some refreshments to be provided? I think we need to have a proper conversation with our guest. In the meantime, I will assign some Ministry people to properly investigate the artifact.” 

“Your highness, the artifact is my property”, the Earl protested. 

Geord turned to the Earl, fixing him with a solid gaze. 

“I am confiscating this artifact in the name of the Kingdom of Sorcier until my fiancée has been safely returned to my side”, Geord stated in a tone that defied all room for protests. “If you wish to contest my decision, I will properly hear it at a later time in the company of the Chancellor. Until then, a good day to you, Earl Elliott.” 


The people of the student council sat down in a private loungeroom with their guest, the possible Princess Sya. The servants had arranged for tea and pastries, which Princess Sya indulged in without reservation. Thinking it best to wait with the questions until she was satisfied, they all tried to attend the occasion as if it were a regular tea party, nothing amiss. There was one person missing from it to make that possible, though. 

Princess Sya drank up her tea and sighed in a satisfied manner. 

“This tea is very soothing...” 

“It is a blend of chamomile”, Mary offered as an explanation. “It is very useful in calming your nerves.” 

She drank a whole teacup of her own, probably to calm her own nerves at the situation. 

Princess Sya nodded to that, eyes half-closed. Deeming it an appropriate time to asking her questions, Geord broke his silence. 

“Pardon my question, Princess Sya, but I feel worried about Lady Katarina Claes, my fiancée. Will the people of your kingdom treat her well until the time we have learned how to bring both of you back to your proper places?” 

“Oh, I wasn’t in my kingdom when I was brought here. I have not been in Goodereste for some years.” She furrowed her brow at that, as if trying to remember something, but seemed to dismiss it the next moment. 

“Oh, were you visiting other kingdoms?” Geord asked, coming up with the most likely reason for a princess to be away for several years. 

“No. I was taken away to be a hostage”, Princess Sya said matter-of-factly. She drank some more tea. 

Everyone else in the room had stilled. They still had not heard anything to disprove any her claims, but if you accepted it as truth, they had just learned that Katarina had swapped places with a hostage. A hostage that probably had been of use to her takers against her kingdom, which Katarina would not be. And more than likely, she might even be mistaken for having set their hostage free. 

“A hostage?” Keith repeated, half in denial. 

“A hostage”, Princess Sya confirmed with a nod. 

“Who are the people who held you hostage?” Geord asked. 

“I was held by the Demon King and his army at the Demon King’s Castle.” 

Everyone looked nonplussed at each other. What was this girl saying? Claiming to have been held hostage by a Demon King? This was not one of Katarina and Sophia’s romance novels. 

Geord felt like calling her out, when a thought occurred to him that stopped him. Maybe she wasn’t being outlandish; many monarchs, chiefs and other rulers had held lavish monikers throughout history, some given by themselves or their people, others by their enemies. A ruler that was an enemy to the kingdom of Goodereste could very well only be referred to as a Demon King or other derogatory titles. Worst case, the title might be a deserved one, and Katarina could be in danger. 

Of course, Sya could still be a dimwitted liar, or pretending to be one, but it still wasn’t time to call her out. 

“Princess Syalis, can you please tell us more about...” 


Geord stilled. In the sofa across from him, the girl had fallen soundly asleep. 

After the initial surprise, Mary, Sophia and Maria made their best efforts, but the girl refused to wake up, and the council had to be left with their mounting worries until the girl would awake on her own. 


Katarina’s side

The light receded. Katarina blinked and looked around. She wasn’t in the lecture hall anymore. It looked like some form of treasury. Gold and jewels were intermingled with weapons and armor and other things she couldn’t easily put a name to. Next on her, on a pedestal, was the artifact from the lecture hall. 

“Who are you?” somebody asked behind her. 

She turned around. 

“Whoa!” she exclaimed in a moment of pure surprise. 

Before her stood two creatures. One looked somewhat like a human, but they had lime green skin and yellow orb for eyes. The other, was like a two-meter-high hedgehog, standing on its hind legs. Both were carrying spears in their hands... yes, the hedgehog had hands, at the end of arms covered in metal armor plate. 

“Who are you?” the hedgehog asked. It was it who had asked before. 

Katarina opened her mouth to answer... and loudly hiccupped. She felt her cheeks warm up. Bother, she had been so suddenly surprised that it had triggered hiccups! She tried to say something again, but all that came out was another hiccup. And another. Soon, she couldn’t stop, each hiccup loudly sounding across the treasury. 

“Whoa, easy!” the hedgehog said in a mollifying tone, raising an arm towards her. 

Katarina looked at him. It was strange that she could read the expression of a two meter hedgehog, but she thought he seemed concerned about her. That made her feel bad for worrying him, but she couldn’t talk because of her hiccups, and she couldn’t stop them by herself. 

“Oh dear...” the hedgehog said, somehow looking awkward. He turned to his companion. “Go get the Demon King and the Elders. We have another disaster on our hands.” 

Katarina noticed that. Demon King? Her otaku knowledge began rising several red flags at that title. 

“Y-yes!” the green man answered, and rushed off. 


The green man soon returned with more people. A dark-hued man with green hair and a pair of black horns dressed in formal clothes and a cape, another man with different-looking horns dressed in ceremonial clothing, a boy with blue skin and weird ears dressed only in loincloth, arm braces and boots, a green-haired woman in an equally green dress and finally a large red-skinned man with a facial mask, tail and claws. 

From what Katarina had heard at a distance while waiting, they had been talking while rushing over here, but at the sight of her when arriving, they had come to a full stop and just stared at her. 

After a couple of long moments, the green-haired man with horns and a cape stepped forward, taking the reins. 

“Who are you?” he asked. 

Katarina hiccupped. 

The man looked dumbfounded at that response. After a moment, Katarina hiccupped again, and the man seemed to come to his senses. 

“Get something for her to drink”, he called over his shoulder to the green man and the hedgehog. 

“At once!” they responded and made an exit. 

They soon returned with a mug of something that they gave to Katarina. She sniffed it. It didn’t smell like alcohol. The scent was familiar, but she didn’t recognize it. She tried a sip. At the taste and the bubbles, she almost dropped the mug in surprise. 


She hadn’t had soda since her last life ended! 

And that... was because no one in her new world made it. 

She felt a deep sense of unease at the thought. 

Where was she? 

She hiccupped again, and seeing the odd people look at her made her hold her breath and gulp all of the soda down in one sweep. She held her breath for a moment, and breathed out when she didn’t hiccup again. 

“Thank you”, she said to the people who had given her the soda. 

She stilled when they seemed astonished at that. 

The man with the green hair stepped forward again. 

“Now, who are you, and where did you come from?” 

“My name is Katarina Claes”, Katarina answered. “I was at the Magic Academy, looking at an exhibit, when it started to flash, and then I was here.” 

“Magic Academy?” the man repeated. “Which Magic Academy?” 

“The Magic Academy of Sorcier”, Katarina answered, a little befuddled. 

Honestly, she didn’t know of any other Magic Academy, though when thinking about it, she didn’t know that much of the world outside of Sorcier either. 

“Sor...cier?” the man repeated slowly, trying out the pronunciation. 

That was a bad sign right there. 

“The Kingdom of Sorcier”, Katarina clarified, trying to keep calm. 

“I have never heard of a kingdom named Sorcier.” 

Keeping calm was getting harder by the minute. From the whole situation, she had obviously been warped somewhere, undoubtedly by the exhibited artifact. The question was where to. 

“Please excuse me, but where am I?” she asked. 

The green-haired man looked hesitantly at her before answering. 

“This is the Demon King’s Castle, in the land of the demons.” 

Demon King’s Castle...? The land of the demons...? 

She had never heard of such thing existing in their world. If it did, surely it would have come up in conversation at some point. 

There certainly wasn’t anything like this in Fortune Lover. It was a fantasy otome game with only human characters, and no mentions of other fantasy tropes other than magic and the old time setting. In comparison, the words here sounded more like some classic console RPG... 

She stilled at her last thought. 

Not like an otome game, but an RPG... The warping artifact... The soda... 

Once, she had lived a life in Japan, on planet Earth. Then, she had been reincarnated into the world of an otome game. Had she now been warped to the world of some other game or story? 

How? Why? What? 

“My apologies, my king!” a new voice sounded down the path, and Katarina’s thoughts were interrupted. 

A new person ran toward them to join the group. Katarina could best describe him as a tall wolfman in a military suit and wearing a small set of spectacles. 

“I was inspecting the dungeons when I heard that the Princess had disappeared!”, the wolfman explained. “Whatever happened–” 

The wolfman caught the sight of Katarina and stilled. The next moment, he starting growling in a deep tone, and Katarina froze in fear. 

“Red, what’s the matter with you?” the Demon King asked in a bewildered voice. Everyone else was looking at the wolfman in equal bewilderment. 

The wolfman stilled, turning his head to the Demon King, suddenly looking deeply confused. 

“My apologies, my king. It is just...” He shook his head. “This girl has a strange presence to her. When I first saw her, I felt as if I had spotted a long time enemy.” 

“A long time enemy?” They looked at Katarina. “She doesn’t appear strong in any combative way.” 

The wolfman shook his head again. 

“Not a strong enemy; a long time enemy. Not from battle, more like a neighbor you can’t stand. I just felt like baring my teeth and chasing her up a tree...” 

“Up a tree?” 

“I... have no idea why I said that.” 

Katarina had noticed something in what the wolfman had said. 

“Excuse me”, she said, and the green-haired man turned back to her. “What was it he called you...?” 

The man’s eyes widened in realization. He suddenly struck a pose, holding out part of his cape with his left hand. 

“I am the Demon King Twilight!” the man proclaimed pompously while holding the pose. 

Katarina stilled at that. So, this guy was the Demon King, huh? Then the question was, what type of Demon King was he? She studied him cautiously, thinking. 

Most old school RPGs only had evil demon kings, out to destroy the world, but she had read plenty of light novels and manga, and watched plenty anime, where the creators shook things up by making the demon king an entirely different type of character, sometimes even a good guy. 

She should probably not make any hasty conclusions. His hedgehog underling didn’t seem like a bad person at first glance, and the Demon King had brought her a soda. 

Seeing Katarina standing there looking at him, not moving a muscle, the Demon King’s face suddenly turned flustered, dropping his cape and awkwardly reaching his arms towards her direction. 

“No, wait... Take it easy. I didn’t mean to...” 

It seemed like he had mistaken her standing still for fear. Seeing his behavior, Katarina felt herself relax. It didn’t seem like the behavior of a bad person. 

“No, it’s fine”, she said. “I was a bit surprised, that is all.” 

The Demon King and everyone else looked at her in surprise. 

“Now, please...” she continued. “Can we sort things out?” 


They talked some more after that, and Katarina got a better picture. 

She had been warped into the treasury of the Demon King’s castle in the land of the demons, a land covered in unending night outside of the human lands. 

The artifact that had been before her when she arrived had apparently been in the treasury for an untold number of years now, regarded as an unidentified curiosity. Comparing their stories, the people of the Demon King’s castle concluded that there must be two artifacts, probably made to transport people between them. 

When she warped in, she had apparently switched places with a princess, Princess Syalis of the kingdom of Goodereste, who had been a hostage at the castle for a number of years. 

They called her a hostage, but when they talked about her, the people around Katarina did not express indignation at losing a hostage, or a concern about how the disappearance of their hostage would affect their situation. 

They seemed worried  about her. 

Seeing this made Katarina relax even more. They really didn’t seem to be bad people. 

Then she had a sobering thought. Her friends and little brother were probably worried about her too right now. 

How were they to solve this? 

The artifact should be able to repeat its feat of swapping Katarina and Princess Syalis. Thing was, by all accounts, no one knew how it worked, or even its origin. 

Katarina had quickly located the symbol square she had pressed before on the other artifact. Unlike with the other artifact, the square wasn’t blinking, and when she to the demons’ alarm pressed the square, nothing happened this time around. 

Presumably, the squares with symbols acted as buttons to control its effects, but the symbols didn’t give a hint of what they stood for, and Katarina’s suggestion to try to press them randomly was swiftly disapproved by the demons. 

“Enough of this”, the Demon King stated resolutely. “We will bring the artifact to one of the laboratories and study it there. Great Red Siberian, assemble all relevant personnel for the task.” 

“At once, my king!” the wolfman responded and set off. 

“Miss Katarina?” the Demon King called carefully. “In all likelihood, our chances of retrieving the Princess will hinge upon your well-being, so for the time being, it is probably best if you rest. Are you fine with this?” 

“Eh, sure”, Katarina nodded. There wasn’t much else so could do in this situation. 

“Where would she rest?” the boy with the blue skin asked. 

“Just bring her to the Princess’ cell for the time being. Inform the personnel that the daily routine stands.” 

After some additional talk, the green man, Castle Grunt Goblin, and the hedgehog, Quilladillo, escorted Katarina away through the castle.